The present invention relates to an image processing system, a projector, a computer-readable storage medium, and an image processing method in which the detection of a projection area is based on sensing information.
A recent proposal for adjusting the position of a projection image involves using a projector that is provided with a CCD camera to project an image onto a projection target such as a screen, and using the CCD camera to sense the projected projection image and detect the coordinates of four corners of the projection-target area that correspond to the projection target within the sensing area.
For example, Japanese Patent Application Laid-Open No. 5-30520 proposes a configuration in which the position at which an image is projected is adjusted by displaying an image within an image-displayable area and sensing the entire image-displayable area.
However, when the configuration is based on the premise that the image is displayed within the image-displayable area, as in Japanese Patent Application Laid-Open No. 5-30520, it will not be possible to adjust the projection position of the image if part of the image is projected outside of the image-displayable area.
In particular, since projectors have become smaller in recent years, users are treating them as mobile projectors by carrying them around and setting them up in other locations to project images. In such a case, restrictions in installation locations could result in part of the projection image being displayed outside the screen. In such a situation, it is necessary to have a projector that can adjust the position of the projection image as appropriate.
In addition, although this Japanese Patent Application Laid-Open No. 5-30520 does disclose the process of detecting the positions of four corners of the displayable area of the screen by fetching luminance information stored in a frame memory into a CPU for image processing, it does not disclose any specific details of that image processing.
When the positions of the four corners of the screen are detected from sensing information during general-purpose image processing used in the art, it is necessary to subject the entire sensed image to filtering processing, which takes time for the image processing and also greatly increases the amount of calculations.
For that reason, calibration is time-consuming and thus the user has to wait for a longer time.